Project Summary/Abstract Sickle cell disease (SCD) is a chronic illness which affects mostly minorities in the United States. It is also a prevalent disease in the Caribbean. Children afflicted with SCD are prone to many complications, such as infections, pain and stroke. Newborn screening and comprehensive care with penicillin prophylaxis and immunizations, among other standard-of-care measures, provide the chance to improve quality of life and give the opportunity for survival. Haiti is one of the poorest countries in the Caribbean which does not count with resources at the present time to implement some of these measures. Haitians are a significant minority in South Florida, and are a third of the patients who attend the University of Miami Sickle Cell Clinic. This application presents the opportunity for collaborative research in database development and cohort surveillance studies for newborns and young children less than 6 years of age with SCD in the United States and Haiti. The research question is to what extent there are differences in incidence and health outcomes in the two geographic areas (Miami in Florida and in several Haiti sites). The proposal has 3 specific aims: 1. Determine the incidence of newborns of Haitian ethnicity with SCD in Miami Dade County using available databases from newborn screening. 2. Expand hospital-based newborn screening with point-of-care device and centralized laboratory screening capability in Haiti so that SCD incidence is confirmed, allowing for comparison with Aim 1. 3. Examine and compare barriers to care and health outcomes of the US-based Haitian ethnic cohort (with African-American sickle cell controls) and Haitian cohorts. We will build on previously obtained data that the incidence of SCD in Haiti among newborns is as high as 1 child out of 125 children born has SCD, and will expand the RED Cap database of children followed in Cap Haitien, Haiti. PhenX standardized measures will be used to expand the database for the Miami and Haitian sites. Demographics, changes in height and weight over time (growth), anemia severity, SCD-related complications including stroke risk according to transcranial Doppler ultrasound testing, treatment adherence, barriers to care via questionnaire assessment, acculturation in Haitian immigrants, and mortality will be collected. The implementation of transcranial Doppler ultrasound (TCD), which is a non- invasive method to screen for stroke risk, will be new in Haiti. We will accomplish this with staff training and tele- mentoring. Central reading will be done at the University of Miami. We expect to learn from and benefit a low resource setting in the Caribbean (Haiti), to impact Haitians living in the US, and promote strong international collaboration.